The process of this invention relates to the production of 4-hydroxy-n-butyraldehyde by the hydrogen fluoride-catalyzed reaction of allyl alcohol and formaldehyde.
4-HYDROXY-N-BUTYRALDEHYDE HAS VARIOUS USES AS AN INTERMEDIATE IN THE PRODUCTION OF ORGANIC COMPOUNDS. For example, 4-hydroxy-n-butyraldehyde is readily hydrogenated to prepare 1,4-butanediol, which is in turn reacted with terephthalic acid to produce a saturated polyester for fiber manufacture. 4-hydroxy-n-butyraldehyde may also be readily cyclized to form 2-hydroxy-tetrahydrofuran.
It is known to produce butyraldehydes from unsaturated alcohols by the "oxo synthesis." The oxo synthesis comprises contacting an olefin with carbon monoxide and hydrogen in the presence of a cobalt salt at elevated temperatures and pressures. A typical example of the use of oxo chemistry to prepare 4-hydroxy-n-butyraldehyde is found in the article of Adkins and Krsek appearing at J. Am. Chem. Soc. 71, 3051-5 (1949). In general, the oxo synthesis proceeds as follows: EQU RCH.sub.2 CH.dbd.CH.sub.2 + CO+ H.sub.2 .fwdarw. R--CH.sub.2 CH.sub.2 CH.sub.2 CHO
gamma-hydroxyaldehydes have also been synthesized from tetrahydrofuran by oxidation to prepare the peroxide which can be decomposed or rearranged to the aldehyde. British Pat. No. 614,392 (1948) is typical of this approach, and particularly suggests the use of cobalt or nickel catalysts to promote oxidation to the peroxide.